More Like this

1. The Gaia–Kepler Stellar Properties Catalog. I. Homogeneous Fundamental Properties for 186,301 Kepler Stars

   https://doi.org/10.3847/1538-3881/159/6/280  

   Berger, Travis A. ; Huber, Daniel ; van Saders, Jennifer L. ; Gaidos, Eric ; Tayar, Jamie ; Kraus, Adam L. ( June 2020 , The Astronomical Journal)

   null (Ed.)
2. Six new rapidly oscillating Ap stars in the Kepler long-cadence data using super-Nyquist asteroseismology

   https://doi.org/10.1093/mnras/stz1633  

   Hey, Daniel R ; Holdsworth, Daniel L ; Bedding, Timothy R ; Murphy, Simon J ; Cunha, Margarida S ; Kurtz, Donald W ; Huber, Daniel ; Fulton, Benjamin ; Howard, Andrew W ( June 2019 , Monthly Notices of the Royal Astronomical Society)
3. The Occurrence of Rocky Habitable-zone Planets around Solar-like Stars from Kepler Data

   https://doi.org/10.3847/1538-3881/abc418  

   Bryson, Steve ; Kunimoto, Michelle ; Kopparapu, Ravi K. ; Coughlin, Jeffrey L. ; Borucki, William J. ; Koch, David ; Aguirre, Victor Silva ; Allen, Christopher ; Barentsen, Geert ; Batalha, Natalie M. ; et al ( December 2020 , The Astronomical Journal)

   Abstract We present the occurrence rates for rocky planets in the habitable zones (HZs) of main-sequence dwarf stars based on the Kepler DR25 planet candidate catalog and Gaia-based stellar properties. We provide the first analysis in terms of star-dependent instellation flux, which allows us to track HZ planets. We define η ⊕ as the HZ occurrence of planets with radii between 0.5 and 1.5 R ⊕ orbiting stars with effective temperatures between 4800 and 6300 K. We find that η ⊕ for the conservative HZ is between (errors reflect 68% credible intervals) and planets per star, while the optimistic HZ occurrence is between and planets per star. These bounds reflect two extreme assumptions about the extrapolation of completeness beyond orbital periods where DR25 completeness data are available. The large uncertainties are due to the small number of detected small HZ planets. We find similar occurrence rates between using Poisson likelihood Bayesian analysis and using Approximate Bayesian Computation. Our results are corrected for catalog completeness and reliability. Both completeness and the planet occurrence rate are dependent on stellar effective temperature. We also present occurrence rates for various stellar populations and planet size ranges. We estimate with 95% confidence that, on average, the nearest HZ planet around G and K dwarfs is ∼6 pc away and there are ∼4 HZ rocky planets around G and K dwarfs within 10 pc of the Sun. 

   more » « less
4. A Green Bank Telescope Search for Narrowband Technosignatures between 1.1 and 1.9 GHz During 12 Kepler Planetary Transits

   https://doi.org/10.3847/1538-3881/aca907  

   Sheikh, Sofia Z. ; Kanodia, Shubham ; Lubar, Emily ; Bowman, William P. ; Cañas, Caleb I. ; Gilbertson, Christian ; MacDonald, Mariah G. ; Wright, Jason ; MacMahon, David ; Croft, Steve ; et al ( January 2023 , The Astronomical Journal)

   A growing avenue for determining the prevalence of life beyond Earth is to search for “technosignatures” from extraterrestrial intelligences/agents. Technosignatures require significant energy to be visible across interstellar space and thus intentional signals might be concentrated in frequency, in time, or in space, to be found in mutually obvious places. Therefore, it could be advantageous to search for technosignatures in parts of parameter space that are mutually derivable to an observer on Earth and a distant transmitter. In this work, we used theL-band (1.1–1.9 GHz) receiver on the Robert C. Byrd Green Bank Telescope to perform the first technosignature search presynchronized with exoplanet transits, covering 12 Kepler systems. We used the Breakthrough Listen turboSETI pipeline to flag narrowband hits (∼3 Hz) using a maximum drift rate of ±614.4 Hz s⁻¹and a signal-to-noise threshold of 5—the pipeline returned ∼3.4 × 10⁵apparently-localized features. Visual inspection by a team of citizen scientists ruled out 99.6% of them. Further analysis found two signals of interest that warrant follow up, but no technosignatures. If the signals of interest are not redetected in future work, it will imply that the 12 targets in the search are not producing transit-aligned signals from 1.1 to 1.9 GHz with transmitter powers >60 times that of the former Arecibo radar. This search debuts a range of innovative technosignature techniques: citizen science vetting of potential signals of interest, a sensitivity-aware search out to extremely high drift rates, a more flexible method of analyzing on-off cadences, and an extremely low signal-to-noise threshold.

    

   more » « less
5. Kepler-167e as a Probe of the Formation Histories of Cold Giants with Inner Super-Earths

   https://doi.org/10.3847/1538-4357/ac3ed6  

   Chachan, Yayaati ; Dalba, Paul A. ; Knutson, Heather A. ; Fulton, Benjamin J. ; Thorngren, Daniel ; Beichman, Charles ; Ciardi, David R. ; Howard, Andrew W. ; Van Zandt, Judah ( February 2022 , The Astrophysical Journal)

   Abstract The observed correlation between outer giant planets and inner super-Earths is emerging as an important constraint on planet formation theories. In this study, we focus on Kepler-167, which is currently the only system known to contain both inner transiting super-Earths and a confirmed outer transiting gas giant companion beyond 1 au. Using long-term radial velocity monitoring, we measure the mass of the gas giant Kepler-167e ( P = 1071 days) to be 1.01 − 0.15 + 0.16 M J , thus confirming it as a Jupiter analog. We refit the Kepler photometry to obtain updated radii for all four planets. Using a planetary structure model, we estimate that Kepler-167e contains 66 ± 19 M ⊕ of solids and is significantly enriched in metals relative to its solar-metallicity host star. We use these new constraints to explore the broader question of how systems like Kepler-167 form in the pebble accretion framework for giant planet core formation. We utilize simple disk evolution models to demonstrate that more massive and metal-rich disks, which are the most favorable sites for giant planet formation, can also deliver enough solids to the inner disk to form systems of super-Earths. We use these same models to constrain the nature of Kepler-167's protoplanetary disk and find that it likely contained ≳300 M ⊕ of dust and was ≳40 au in size. These values overlap with the upper end of the observed dust mass and size distributions of Class 0 and I disks and are also consistent with the observed occurrence rate of Jupiter analogs around Sun-like stars. 

   more » « less